• Leica Geosystems Total Station TS11, with a distance
accuracy of 2 mm and angular 2 ppm Leica Viva TS11 Datasheet, 2010
• Leica Geosystems 3D scanning device, model C10
with a point to point accuracy of 6 mm position and 4 mm distance Leica ScanStation C10 DS, 2011
• Digital Photogrammetry using high-resolution Nikon
D800 DSLR camera with 36 MP Nikon D800, 2014 and a DJI Phantom 2 Vision, which is a low cost
Unmanned Aerial Vehicle UAV Phantom 2 Vision Specs, 2015
Furthermore, in order to obtain record and panoramic photography for capturing architectural, condition and character
defining views and details images were captured using the high-resolution Nikon D800 DSLR camera with 36 MP Nikon
D800, 2014 and a Nikon D300 DSLR with 12 MP. For panoramic photography a Nodal Ninja adapter was used.
Additionally giga pixels images were generated using a Gigapan adapter and software.
2.2 Recording approach
The measured drawings and other deliverables were produced using different recording tools in order to maximize the
documentation of the site given the onsite and office timeframe available.
The fieldwork consisted of 17 days of on-site recording in two separate missions June-July and September 2014, primarily
using the previously described direct and indirect surveying techniques. The compilation of the baseline record of Beinn
Bhreagh Hall was implemented through the following steps:
• Establishment of a surveying network
• Recording the building: exterior and interior
• Site boundary and buffer zone
• Site Photographic portfolio
• Post recording production: two-dimensional drawing
CAD, BIM modelling •
Structural and sustainability performance audit Upon returning to Ottawa, the team processed the collected
information using
Computer-Aided Drafting, Building
Information Modelling and image processing applications for the preparation of the requested deliverables.
The deliverables, such the Building Information Modelling BIM models were further used in structural and sustainability
simulations.
2.3 Surveying network: Setting up a reliable coordinate system
The TS11 Total station was used to geometrically link the 3D scanning, photogrammetric record and the survey of the
individual spaces plans, elevations and sections.
This Total Station is an Electronic Distance Measurement EDM tool, that after being properly levelled in a fix measuring
point and orientated using a base bearing from a second measuring post bench-mark or standpoint records measured
points by projecting an infrared beam EDM mode to a prism rod reflector, or a laser beam to a surface up to 80-300 m from
its position REDM mode. This action calculates three- dimensional co-ordinates, and if required, other geodetic
information between the point and the original reference point, such as angles, distances, different of heights.
For this reason, this instrument was used to survey a network of fixed points from the interior and exterior perimeter of the
house as well as its immediate surroundings. A local coordinate system was created by orientating the survey to magnetic north.
As such, a future professional surveyor could attach this network to the National Canadian grid by matching selected
base points from the local system to the National network.
The first stage of the survey was to establish an outer ring of control points measured around the house. Secondly, control
points were measured using washers painted in red and glued to selected areas around outer elevations of the house with epoxy.
Thirdly, photogrammetric controls were measured using inherent features of the house; this prevented unnecessary
gluing of targets. Finally, an inner coverage of control points was measured using target stickers. These three networks of
points allowed tightening a network of controls to link the different surveying techniques.
2.4 Recording the Building’s envelop and Interior spaces A combination of 3D scanning and photogrammetry was used
to capture the geometric configuration of the house and its immediate surroundings. As previously explained, the 3D
scanning device was used to capture a dense point cloud of the scene being surveyed from different positions. To complete the
set of reliable measurements, photogrammetry was used to take elevated photographs in order to capture those elements
invisible to the scanner by employing both an Unmanned Aerial Vehicle UAV and an Aerial Lift Work Truck. From the
photogrammetric models of the roof and elevations it was possible to produce a mesh model and dense point clouds. The
resulting point clouds from both techniques were combined in specialized Computer Aided Drafting CAD and Building
Information Modeling BIM software for the processing phase of this documentation project.
2.5 Site topography In order to measure and represent the immediate topography of
the terrain, the team proceeded to record the home’s immediate surroundings using laser scanning as a way of documenting this
important landmark’s location and orientation.
Fig.3 – Beinn Bhreagh 3D topography from pointclouds
2.6 Detailed 3D Scanning 3D scanning applications produce three-dimensional
information in the form of point cloud data. Hundreds or thousands of points are collected from a scanned surface and
can be used to create digital drawings or models. Laser scanning
25th International CIPA Symposium 2015, 31 August – 04 September 2015, Taipei, Taiwan
This contribution has been peer-reviewed. The double-blind peer-review was conducted on the basis of the full paper. doi:10.5194isprsannals-II-5-W3-235-2015
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techniques yield highly accurate data in a relatively short time frame. Each laser-scanning scenario can record a 360-degree
environment.
In order to efficiently acquire data from the Beinn Bhreagh Hall site, the project team utilized a “time-of Flight” device which,,
according to English Heritage allows users “to survey building façades and interiors, resulting in line drawings with
supporting data and surface models” English heritage, 2007.
Furthermore, this type of scanning device acquires measurements by using a “two-way travel time of a pulse of
laser energy to calculate a range.” As a result, “This type of scanner can be expected to collect many tens of thousands of
points every minute by deflecting this laser pulse across the surface of an object, using a rotating mirror or prism“ English
Heritage, 2007.
Böhler and Marbs generically describe a laser scanner as a “device that collects 3D co-ordinates of a given region of an
object’s surface automatically and in a systematic pattern at a high rate hundreds or thousands of points per second
achieving the results ie three-dimensional co-ordinates in near real time.” Böhler Marbs, 2002 Several sets of
point cloud data can be merged together from separate scanning exercises if controlled survey points are established. From the
combined point cloud data, detailed three-dimensional models can be generated.
A crucial issue in laser scanning historic surfaces is “determining appropriate point density” English Heritage,
2011 for the correct preparation of measured drawings and 3d models that will reveal geometric information relevant to
conservation practices and the desired graphic scale. According to English Heritage, 35 mm is the optimal resolution interval
“for point density required to give 66 probability that the feature will be visible” English Heritage, 2011. For this reason
the CIMS team conducted the survey using higher resolution intervals to ensure the integrity of the data for the production
of the required graphic deliverables where the final resolution selected was 0.05m x 0.05m at 100m for exterior spaces, and
0.1m x 0.1m at 100m for interior spaces.
2.7 Aerial and terrestrial photogrammetry
